This proposal seeks a five-year continuation of Monitoring the Future, an ongoing epidemiological research and reporting project. Begun in 1975, the project functions as a basic research study, as well as one of the nation's major sources of reliable information on trends in drug use. It has been based on two interconnected series of surveys using nationally representative samples: (a) an annual survey of seniors in high schools (about 17,000 per year in 135 high schools), and (b) annual follow-up surveys of panels (of about 1,200 people from each graduating class), followed by mail for a period that will reach 17 years past high school. It is proposed to continue these surveys of American high school students, and young adult graduates through age 35, including college students. In 1991, national samples of 8th and 10th grade students were added to the annual surveys; a continuation of this series is also proposed. In addition, it is now proposed that biennial follow-ups of panels be drawn from each 8th and 10th grade class, with an oversampling of the dropout-prone, in order to provide accurate assessments of: (a) levels and trends in drug use among dropouts, (b) the influence of drug use on dropping out and vice versa, and (c) the changing etiology of drug use in early to middle adolescence. The study's cohort-sequential design permits the differentiation of three types of change over time-secular, maturational, and cohort-each of which tends to have quite different types of determinants, and all of which have already been found to occur for at least some drugs. In addition to monitoring drug use, and many factors which may help to explain secular trends in use, the project has the objectives of documenting the natural history of drug use through these portions of the life cycle, determining what transitions in social roles and social environments contribute to that history, and determining what features of those roles and environments are of particular importance. The project also seeks to ascertain the importance of many other hypothesized psychological, behavioral, and social determinants of drug use (including attitudes and beliefs about drugs, and various lifestyle orientations) as well as a range of potential consequences of drug use (including physical health, psychological well-being, status attainment, and role performance). The fact that these multiple aims and multiple populations are encompassed in a single, integrated study is both synergistic and cost effective. The measurement content contained in the study's multiple questionnaire forms includes (a) a very broad range of licit and illicit drugs; (b) perceived availability, perceived peer norms, and attitudes and beliefs regarding many of these drugs; (c) a number of characteristics of the person (behaviors, attitudes, beliefs, health symptoms, achievements, lifestyle variables); and (d) aspects of key social environments (school, job, college, home) and of role statuses and experiences (marriage, pregnancy, parenthood, divorce, education, employment, and military service). The study will continue to produce a wide range of publications, including NIDA-published annual monographs, annual volumes of descriptive results, special reports and monograph chapters, and journal articles.